In the Caerphilly and Speedwell studies, 2 512 and 2 348 men, respectively, who were 45-59 y of age were seen in the initial cross-sectional phase and at follow-up intervals of 10 y. Adjusted odds ratios of 1.1 (95% confidence interval=0.6,1.9) and 0.9 (95% confidence interval=0.6,1.4) were found in the total cohorts.

However, the relative risk was 1.3 (95% confidence interval=0.8,2.2) in the pooled reconstructed cohort of men who were followed for 6 y (i.e., from phase 2 to phase 3) and for whom room orientation and window-opening habits could be considered.

Furthermore, the relative risk increased to 1.6 (95% confidence interval=0.9,3.0) in the subsample of men who had lived at least 15 y in their present homes at the time of recruitment.

Living adjacent to streets with high traffic noise levels was associated with an adjusted (for covariates) increase in relative risk of 1.01-1.02/y in residence-a result that was only borderline significant (p